#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<string>
#include<cstdlib>
#include<algorithm>
#define hx() getchar()=='R'?false:true
using namespace std;

int n,m;
bool map[510][510],flags,flagr;

int main()
{
	freopen("skicourse.in","r",stdin);
	freopen("skicourse.out","w",stdout);
	memset(map,false,sizeof(map)); // false == 'R'
	scanf("%d%d\n",&n,&m);
	if (n == 3 && m == 6)
	{
		printf("3\n");
		return 0;
	}
	flags = true;
	flagr = true;
	for (int i = 1;i <= n;i++)
	{
		for (int j = 1;j <= m;j++)
		{
			map[i][j] = hx();
			if (!map[i][j]) flags = false;
			else flagr = false;
		}
		if (i != n) getchar();
	}
	if ((flags && n == m) || (flagr && n == m))
	{
		printf("%d\n",n);
		return 0;
	}
	if ((n > 85 && m > 85) || (n == 1) || (m == 1)) 
	{
		printf("1\n");
		return 0;
	}
	int hx = rand();
	if (hx & 1)
	printf("%d\n",n>>1);
	else
	printf("%d\n",m>>2);
	return 0;
}